bridge(s):
A link or connection between two objects - usually places either side of an obstacle, such as a river, chasm, or estuary.dge:

Types of Bridges

bridgetypes (1).jpg

What are the benefits of bridges?

Some of the benefits of bridges are obvious: supplies of food and traded goods can get across an obstacle or through difficult terrain in a shorter time.


The materials used to make bridges are:

Wood, stone, brick, cast iron, wrought iron, steel, concrete, aluminum, and others. The most important material is stone.

Bridge construction technology , steel bridges were riveted together, not bolted, concrete bridges were cast in place, not precast; and large bridge members were built from lacing bars and smaller sections, not rolled in one piece.



http://en.structurae.de/structures/stype/index.cfm?id=1